Abstract
During night times, drivers are highly dependent on road marking retroreflectivity for delineation. Technically speaking, retroreflectivity, which equals to luminance, means the amount of light ray that entered glass beads and reflected to drivers. It has been recommended that the retroreflectivity is evaluated, monitored and controlled at implementation stage or during maintenance. For this reason, the minimum retroreflectivity is postulated based on regulations such as “Polices' Manual on Traffic Safety” and “Manual on Roads” in Korea. This study focuses on the drivers' responses for the minimum retroreflectivity. Subjective evaluations by 49 subjects and quantitative measurements of pavement marking samples especially manufactured with various ranges of retroreflecivity were made in KHC Test Road. The effects of color and material retroreflectivity range were considered. After completion of the experiment, the minimum in-service level, 130∼140 mcd/m2/lux for white markings and 100∼110 mcd/m2/lux for yellow markings, from a driver's point of view was established.
